DRUG INTERACTIONS: Tell your doctor of all prescription and nonprescription medication you may use, especially: azathioprine, mercaptopurine, "blood thinners" (e.g., dicumarol, warfarin), penicillin antibiotics (e.g., ampicillin, amoxicillin), "water pills" (e.g., furosemide, hydrochlorothiazide), chlorpropamide, cyclosporine, probenecid, sulfinpyrazone, anti-cancer drugs. Tell your doctor if you take any drugs that cause drowsiness such as: medicine for sleep, sedatives, tranquilizers, anti- anxiety drugs (e.g., diazepam), narcotic pain relievers (e.g., codeine), psychiatric medicines (e.g., phenothiazines or tricyclics), anti-seizure drugs (e.g., carbamazepine), muscle relaxants, certain antihistamines (e.g., diphenhydramine). Check the label on all your medicines (e.g., cough-and-cold products) because they may contain drowsiness-causing ingredients. Ask your pharmacist about the safe use of these products. Do not start or stop any medicine without doctor or pharmacist approval.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly.

NOTES: Do not share this medication with others. Laboratory and/or medical tests may be performed to monitor your progress. If you take the oral form of allopurinol, inform your doctor.

MISSED DOSE: If you miss a dose, use it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

STORAGE: Store unmixed/powder vials at room temperature between 68 and 77 degrees F (20 and 25 degrees C). After mixing and further dilution with IV fluids, this product is stable for 10 hours at room temperature. Do not refrigerate the mixed vial or diluted solution. Discard any unused portion of the vial.

Report Problems to the Food and Drug Administration You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088. Need help identifying pills and medications? Use the pill identifier tool on RxList.